This means EVERY AC operated product under the scope of EN 61000-3-3:2008 must be re-assessed, test report modified if necessary or technical justification prepared for the Technical File if no retest is done and a new EU DoC updated to reflect this change!
Most older test equipment used to measure flicker would not have been rated with EN61000-4-15:2011 (new method called in EN 61000-3-3:2013) as such it may be necessary to retest to the new standard or make a technical justification.
Its recommended that you check with the test house that originally tested your equipment, it may also say in your original test report.
If required we can now retest to the latest standard at our facility for you.